1 files changed, 289 insertions, 0 deletions
diff --git a/src/de/mod.rs b/src/de/mod.rs
new file mode 100644
index 0000000..09ea120
--- /dev/null
+++ b/src/de/mod.rs
@@ -0,0 +1,289 @@
+//! Deserializing TOML into Rust structures.
+//!
+//! This module contains all the Serde support for deserializing TOML documents into Rust structures.
+
+use serde::de::DeserializeOwned;
+
+mod array;
+mod datetime;
+mod key;
+mod spanned;
+mod table;
+mod table_enum;
+mod value;
+
+use array::ArrayDeserializer;
+use datetime::DatetimeDeserializer;
+use key::KeyDeserializer;
+use spanned::SpannedDeserializer;
+use table::TableMapAccess;
+use table_enum::TableEnumDeserializer;
+
+pub use value::ValueDeserializer;
+
+/// Errors that can occur when deserializing a type.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Error {
+    inner: crate::TomlError,
+}
+
+impl Error {
+    pub(crate) fn custom<T>(msg: T, span: Option<std::ops::Range<usize>>) -> Self
+    where
+        T: std::fmt::Display,
+    {
+        Error {
+            inner: crate::TomlError::custom(msg.to_string(), span),
+        }
+    }
+
+    /// Add key while unwinding
+    pub fn add_key(&mut self, key: String) {
+        self.inner.add_key(key)
+    }
+
+    /// What went wrong
+    pub fn message(&self) -> &str {
+        self.inner.message()
+    }
+
+    /// The start/end index into the original document where the error occurred
+    pub fn span(&self) -> Option<std::ops::Range<usize>> {
+        self.inner.span()
+    }
+
+    pub(crate) fn set_span(&mut self, span: Option<std::ops::Range<usize>>) {
+        self.inner.set_span(span);
+    }
+}
+
+impl serde::de::Error for Error {
+    fn custom<T>(msg: T) -> Self
+    where
+        T: std::fmt::Display,
+    {
+        Error::custom(msg, None)
+    }
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.inner.fmt(f)
+    }
+}
+
+impl From<crate::TomlError> for Error {
+    fn from(e: crate::TomlError) -> Error {
+        Self { inner: e }
+    }
+}
+
+impl From<Error> for crate::TomlError {
+    fn from(e: Error) -> crate::TomlError {
+        e.inner
+    }
+}
+
+impl std::error::Error for Error {}
+
+/// Convert a value into `T`.
+pub fn from_str<T>(s: &'_ str) -> Result<T, Error>
+where
+    T: DeserializeOwned,
+{
+    let de = s.parse::<Deserializer>()?;
+    T::deserialize(de)
+}
+
+/// Convert a value into `T`.
+pub fn from_slice<T>(s: &'_ [u8]) -> Result<T, Error>
+where
+    T: DeserializeOwned,
+{
+    let s = std::str::from_utf8(s).map_err(|e| Error::custom(e, None))?;
+    from_str(s)
+}
+
+/// Convert a document into `T`.
+pub fn from_document<T>(d: crate::Document) -> Result<T, Error>
+where
+    T: DeserializeOwned,
+{
+    let deserializer = Deserializer::new(d);
+    T::deserialize(deserializer)
+}
+
+/// Deserialization for TOML [documents][crate::Document].
+pub struct Deserializer {
+    input: crate::Document,
+}
+
+impl Deserializer {
+    /// Deserialization implementation for TOML.
+    pub fn new(input: crate::Document) -> Self {
+        Self { input }
+    }
+}
+
+impl std::str::FromStr for Deserializer {
+    type Err = Error;
+
+    /// Parses a document from a &str
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let d = crate::parser::parse_document(s).map_err(Error::from)?;
+        Ok(Self::new(d))
+    }
+}
+
+// Note: this is wrapped by `toml::de::Deserializer` and any trait methods
+// implemented here need to be wrapped there
+impl<'de> serde::Deserializer<'de> for Deserializer {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let original = self.input.original;
+        self.input
+            .root
+            .into_deserializer()
+            .deserialize_any(visitor)
+            .map_err(|mut e: Self::Error| {
+                e.inner.set_original(original);
+                e
+            })
+    }
+
+    // `None` is interpreted as a missing field so be sure to implement `Some`
+    // as a present field.
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let original = self.input.original;
+        self.input
+            .root
+            .into_deserializer()
+            .deserialize_option(visitor)
+            .map_err(|mut e: Self::Error| {
+                e.inner.set_original(original);
+                e
+            })
+    }
+
+    fn deserialize_newtype_struct<V>(
+        self,
+        name: &'static str,
+        visitor: V,
+    ) -> Result<V::Value, Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let original = self.input.original;
+        self.input
+            .root
+            .into_deserializer()
+            .deserialize_newtype_struct(name, visitor)
+            .map_err(|mut e: Self::Error| {
+                e.inner.set_original(original);
+                e
+            })
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        name: &'static str,
+        fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let original = self.input.original;
+        self.input
+            .root
+            .into_deserializer()
+            .deserialize_struct(name, fields, visitor)
+            .map_err(|mut e: Self::Error| {
+                e.inner.set_original(original);
+                e
+            })
+    }
+
+    // Called when the type to deserialize is an enum, as opposed to a field in the type.
+    fn deserialize_enum<V>(
+        self,
+        name: &'static str,
+        variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        let original = self.input.original;
+        self.input
+            .root
+            .into_deserializer()
+            .deserialize_enum(name, variants, visitor)
+            .map_err(|mut e: Self::Error| {
+                e.inner.set_original(original);
+                e
+            })
+    }
+
+    serde::forward_to_deserialize_any! {
+        bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string seq
+        bytes byte_buf map unit
+        ignored_any unit_struct tuple_struct tuple identifier
+    }
+}
+
+impl<'de> serde::de::IntoDeserializer<'de, crate::de::Error> for Deserializer {
+    type Deserializer = Deserializer;
+
+    fn into_deserializer(self) -> Self::Deserializer {
+        self
+    }
+}
+
+impl<'de> serde::de::IntoDeserializer<'de, crate::de::Error> for crate::Document {
+    type Deserializer = Deserializer;
+
+    fn into_deserializer(self) -> Self::Deserializer {
+        Deserializer::new(self)
+    }
+}
+
+pub(crate) fn validate_struct_keys(
+    table: &crate::table::KeyValuePairs,
+    fields: &'static [&'static str],
+) -> Result<(), Error> {
+    let extra_fields = table
+        .iter()
+        .filter_map(|(key, val)| {
+            if !fields.contains(&key.as_str()) {
+                Some(val.clone())
+            } else {
+                None
+            }
+        })
+        .collect::<Vec<_>>();
+
+    if extra_fields.is_empty() {
+        Ok(())
+    } else {
+        Err(Error::custom(
+            format!(
+                "unexpected keys in table: {}, available keys: {}",
+                extra_fields
+                    .iter()
+                    .map(|k| k.key.get())
+                    .collect::<Vec<_>>()
+                    .join(", "),
+                fields.join(", "),
+            ),
+            extra_fields[0].key.span(),
+        ))
+    }
+}